Method of manufacturing a safety shoe



Sept. 6, 1966 M|LNER 3,270,358

METHOD OF MANUFACTURING A SAFETY SHOE Filed Sept. 25, 1962 G. M. MILNER INVENTOR.

BY 23* 1 M 1424 United States Patent 3 270,358 METHOD OF MANUFACTURING A SAFETY SHOE George M. Milner, Waynesville, N.C., assignor to R- Search, Inc., Waynesville, N.C., a corporation of North Carolina Filed Sept. 25, 1962, Ser. No. 226,122 2 Claims. (Cl. 12-142) It is customary in the manufacture of various types of footwear to insert into the shoe various internal components to strengthen the shoe or to provide protection for the foot of the wearer of the shoe. Examples of these internal components or inserts are box toes to stiffen the toe of the shoe, counters to stiffen the quarter or heel portion of the shoe, shanks to stiffen the instep of the sole and rigid toe caps to protect the toes of the wearer. These internal components are made from fibers, plastic, steel, and various other materials. The components are held in place by use of adhesives, heat sealing, stitching, or formation of a pocket within the shoe itself to hold them. A major problem associated with the use of these components occurs within the shoe where these materials terminate. In this area an appreciable step or discontinuity is created which may cause irritation to the foot of the wearer. In some cases this difficulty is overcome [by beveling or s'kiving the edge of the internal component. In the case of a steel toe cap this vbeveling is difficult to achieve because of the hardness of the material and is undesirable because it creates a cutting edge in the event of an accident.

One object of the invention is to provide a smooth, stepless transition (i.e., smooth uninterrupted surface) from the edge of the internal component down to the normal thickness of the shoe upper. Another object of the invention is to provide a simple and inexpensive means for anchoring the internal component and holding it in its proper place in the shoe. Other objects of the invention are clarified .by the drawings. FIG. 1 shows a cross section of a shoe provided with a customery steel toe cap. FIG. 2 shows the same cross section with the application of the laminating material according to the invention.

Usually the pre-formed steel safety toe cap 3 is placed into a pocket formed by the upper 1, usually leather, and the inner lining 5. This pocket is closed by a stitching 7 and frequently a thin layer 2 of felt is placed between the steel and the leather of the upper. Where the steel and the felt layer end, a step 5 is created which is not only bothersome for the foot, but also causes damage to the leather upper at this location.

As shown in FIG. 2 this step is avoided when according to the invention the edge of the toe cap 3 atbuts against an elastomeric layer 6, such as rubber, which not only unites the upper and the lining and closes the pocket containing the toe cap, but also assures a gradual and stepless transition 4, presenting a smooth uninterrupted surface, from the area of thickness of the toe cap to the area without it. The laminating layer 6 might extend on one or both sides of the toe cap itself so as to bond it by its adhesive qualities to the upper 1 and/or its lining 5.

3,270,358 Patented Sept. 6, 1966 The gradual transition without step from the area of a re-enforcemen=t to the adjoining area of the upper lby means of an elastomeric bonding layer of decreasing thickness might not only be used for toe caps and box toes, but will bring also substantial improvement when used for counters.

Many methods of manufacture of footwear provide that the upper is heated while held under tension, in order to give the upper permanent shape. According to the invention, the curing of the laminating layer holding the insert in its place can be carried out simultaneously with the shaping of the upper. When this operation is carried out simultaneously with the molding and curing of an elastometnic sole 8, only a single operation is needed to accomplish all three steps, i.e. the curing of the sole, the curing of the laminating layer and the shaping of the upper.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of manufacturing a safety shoe with an elastomeric sole molded and bonded and having a rigid toe cap positioned between the upper and lining of a vamp which includes the steps of placing a filler of elastomeric material at the rear edge of the toe cap between the upper and the lining before the sole is molded and bonded, and simultaneously curing said elastomeric material and molding and .bonding the elastomeric sole to the vamp to produce a smooth stepless uninterrupted surface on the inside of the vamp.

2. The method of manufacturing a safety shoe with an elastomeric sole molded and bonded and having a rigid toe cap positioned between the upper and the lining of a vamp which includes the steps of placing a filler of elastomeric material at the rear edge of the toe cap between the upper and lining before the sole is molded and bonded, and simultaneously curing said elastomenic material, shaping the upper and molding and bonding the elastomeric sole to the vamp to produce a smooth stepless uninterrupted surface on the inside of the vamp.

References Cited by the Examiner UNITED STATES PATENTS 1,659,827 2/ 1928 May 36-77 2,394,216 2/ 1946 Susswein 3 6-77 2,578,987 12/ 1951 Shultz 36-77 2,740,209 4/ 1956 Shultz 36-77 2,756,519 7/ 1956 Hill 36-77 2,795,868 6/1957 Shultz 36-77 FOREIGN PATENTS 1,211,789 :10/19'59 France. 1,213,077 10/ 1959 France.

739,094 10/195 5 Great Britain.

FRANK J. COHEN, Primary Examiner.

EDWARD V. BEN'HAM, Examiner.

P. D. LAWSON, Assistant Examiner. 

1. THE METHOD OF MANUFACTURING A SAFETY SHOE WITH AN ELASTOMERIC SOLE MOLDED AND BOUNDED AND HAVING A RIGID TOE CAP POSITIONED BETWEEN THE UPPER AND LINING OF A VAMP WHICH INCLUDES THE STEPS OF PLACING A FILLER OF ELASTOMERIC MATERIAL AT THE REAR EDGE OF THE TOE CAP BETWEEN THE UPPER AND THE LINING BEFORE THE SOLE IS MOLDED AND BONDED, AND SIMULTANEOUSLY CURING SAID ELASTOMERIC MATERIAL AND MOLDING AND BONDING THE ELASTOMERIC SOLE TO THE VAMP TO PRODUCE A SMOOTH STEPLESS UNINTERRUPTED SURFACE ON THE INSIDE OF THE VAMP. 